1. Field of the Invention
The present invention relates to a washing method for a workpiece, and washing and manufacturing methods for a resin molded product.
2. Related Background Art
Conventionally, it is a common practice to wash a mold releasing agent adhering to the surface of a resin molded product (for example, a conveying guide for use in a paper discharging portion for a laser beam printer) in a washing step, which are obtained by molding a resin material in a molding step, before the product is coated in a coating step (one of the surface treatment steps), wherein a freon is generally used in the cleaning step because it is harmless, non-inflammable, and inexpensive.
However, since the freon destroys the ozone layer, an international regulation of freon has been carried out since 1989, and there is urgent necessity for the development of the washing method not using the freon. One of the washing methods not using the freon relies on the use of a detergent water.
However, since the washing method using the detergent water requires rinsing for removing the detergent water adhering to the surface of resin molded product after washing, a problem arises in connection with the drainage of a large amount of water used in rinsing.
Said problem also arises in removing unnecessary matters adhering to the surface of a workpiece made of e.g. glass with the detergent water.